Method of manufacturing dies and molds by melting-spray

ABSTRACT

A method of manufacturing die and mold by melting-spray relates to a method of manufacturing die and mold used for plastic or metal shaping, in which there is no need for the operating procedure of replicating a melting-sprayed prototype from a prototype or from a rubber die which is reproduced from the prototype. The present invention includes the following steps: (1) directly manufacturing the melting-sprayed prototype; (2) forming a melting-spray layer on the surface of the melting-sprayed prototype; (3) reinforcing the melting-spray layer; and (4) removing the melting-sprayed prototype and then obtaining the die or mold. With this invention, the fast manufacturing speed, the low cost and the improved precision are obtained, and the existent operating procedure for manufacturing die and mold by melting-spray is shortened, thereby it is suitable for manufacturing die and mold used for plastic or metal shaping.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to China Patent Application No. 03119035.9, entitled “Method of Manufacturing Die and Mould by Melting Spray”, to Zhang, et al., filed on 5 May 2003, and the specification thereof is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention (Technical Field)

[0003] The present invention relates to a method of manufacturing a die and mold used for shaping plastic or metal.

[0004] 2. Background Art

[0005] The basic method of manufacturing a die and mold by melting-spray, such as thermal spray, has a fast manufacturing speed and a low cost. In current melting-spray techniques, a melting-sprayed prototype is generally replicated directly from an original prototype. Alternatively, a silicon rubber die is first reproduced from the prototype, and then the melting-sprayed prototype is replicated within the silicon rubber die. A melting-spray layer then is formed on the surface of the melting-sprayed prototype, reinforced and finally removed. As a result, a metal die or mold can be obtained, as described in the 6^(th) International Tooling Conference Key Note Presentations, Karlstad University 10-13 Sep. 2002 (www.itc 2002.kau.se).

[0006] The “Sprayform Tooling Process.” A method for manufacturing a metal die or mold by melting-spay is disclosed in Chinese Patent No. 9911649.0, in which a metal die or mold with high quality and durability can be made by changing the material of the melting-sprayed prototype, followed by changing the material of the melting-sprayed layer. However, a prototype still must be made first to replicate a melting-sprayed prototype from the prototype.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating a preferred embodiment of the invention and are not to be construed as limiting the invention. In the drawings:

[0008]FIG. 1 is a process flow chart of the conventional method of manufacturing a metal die or mold by melting spray; and

[0009]FIG. 2 is a process flow chart of the method according to this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS (BEST MODES FOR CARRYING OUT THE INVENTION)

[0010] The present invention provides a method of manufacturing die and mold by melting-spray, in which there is no need for the process of replicating a melting-sprayed prototype from the initial prototype, or from a rubber die which is previously reproduced from the prototype. On the contrary, in the present invention the melting-sprayed prototype can be directly manufactured to shorten the overall operating procedure.

[0011] The invention provides a method of manufacturing die and mold by the melting-spray process, including the following steps: (1) directly manufacturing a melting-sprayed prototype; (2) forming a melting-spray layer on the surface of the melting-sprayed prototype; (3) reinforcing the melting-spray layer; and (4) removing the melting-sprayed prototype and then obtaining the die or mold.

[0012] According to general methods of manufacturing die and mold by melting-spray, the invention is further characterized in that the melting-sprayed prototype is made by removing material through machining, or by material-accumulated shaping.

[0013] According to the inventive method of manufacturing die and mold by melting-spray, the material of the melting-sprayed prototype may be metal, ceramic powder or mixed powder of both.

[0014] According to the inventive method of manufacturing die and mold by melting-spray, the material for forming the melting-spray layer may be carbide alloy or wear resistant metal, and the material for reinforcing the melting-spray layer may be casting alloy.

[0015] According to the inventive method of manufacturing die and mold by melting-spray, the ceramic powder used by the melting-sprayed prototype may be alumina or silicon dioxide; the material for forming the melting-spray layer may be tungsten carbide alloy, stainless steel or nickel alloy, and the material used for reinforcement may be bismuth alloy or zinc alloy.

[0016] Compared with the conventional method of manufacturing die and mold by melting-spray, the operating procedure of the present invention is shortened and thus has the following advantages: (1) the speed of manufacturing the die or mold is increased, because the shortening of overall operating procedure reduces the time for manufacturing the die or mold; (2) the cost is lowered due to eliminating the need for using the prototype and the rubber die, and thus the material for manufacturing the die or mold and the labor cost are reduced; (3) the precision of the manufacture of the die or mold is improved, because the shortening of the operating procedure eliminates the precision loss caused by replication during the die manufacturing.

[0017] Embodiment 1

[0018] (1) A metallic copper powder and binding agent are mixed together and agitated to be uniform, following by being poured in a pouring frame; and then waiting until the uniform mixture in the pouring frame is solidified to the blank whose shape can be fixed.

[0019] (2) Removal-type machining is applied to the blank, according to the desired shape of the prototype, to obtain the melting-spray prototype. After preheating, the surface of the melting-spray prototype can be melting-sprayed, thereby forming the melting-spray layer with the desired performances.

[0020] (3) Tungsten carbide alloy powder is melting-sprayed on the surface of the melting-sprayed prototype, forming a tungsten carbide alloy layer with the thickness of about 0.3 mm.

[0021] (4) Melting-sprayed layer is reinforced by the use of bismuth-tin alloy casting. To improve the effect of cooling, a cooling pipeline may be provided in the reinforced part.

[0022] (5) The melting-sprayed prototype is broken and separated from the melting-spray layer, thereby yielding the die or mold which has the surface of tungsten carbide alloy. Sequential finish machining can be carried out by the use of general methods, such as machining.

[0023] Embodiment 2

[0024] (1) An alumina powder and binding agent are mixed together and agitated to a uniform mixture.

[0025] (2) Through an extrusion device, the melting-spray prototype is not finished by piling-up and accumulating material on a base plate until the desired shape of the prototype is formed. After preheating, the surface of the melting-spray prototype is melting-sprayed, thereby forming the desired melting-spray layer.

[0026] (3) Stainless steel powder is melting-sprayed on the surface of the melting-sprayed surface, and a stainless steel layer with the thickness of about 0.5 mm is formed.

[0027] (4) With the same method as that of embodiment 1 above, the melting-sprayed layer is reinforced by the use of bismuth-tin alloy casting.

[0028] (5) The melting-sprayed prototype is broken and separated from the melting-spray layer, so that a die or mold having a surface of stainless steel is obtained. Sequential finish machining can be carried out by the use of generally known methods, such as machining. 

What is claimed is:
 1. A method of manufacturing die or mold by a melting-spray process, comprising: directly manufacturing a melting-sprayed prototype; forming a melting-spray layer on the surface of the melting-sprayed prototype; reinforcing the melting-spray layer; and removing the melting-sprayed prototype and then obtaining the die or mold.
 2. The method of manufacturing die or mold according to claim 1, characterized in that the melting-sprayed prototype is manufactured by removal-type machining,
 3. The method of manufacturing die or mold according to claim 1, characterized in that the melting-sprayed prototype is manufactured by material-accumulated shaping.
 4. A method of manufacturing die and mold according to claim 1, characterized in that the material of the melting-sprayed prototype is selected from the group consisting of metal, ceramic power, and a powder of mixed metal and ceramic.
 5. A method of manufacturing die and mold according to claim 4, characterized in that the material for forming the melting spray is selected from the group consisting of carbide alloy and wear resistant metal, and the material for reinforcing the melting spray layer comprises casting alloy.
 6. A method of manufacturing die and mold according to claim 5, wherein the ceramic power used in the melting-sprayed prototype is selected from the group comprising alumina and silicon dioxide, the material for forming the melting-spray layer is selected from the group comprising tungsten carbide alloy, stainless steel and nickel alloy, and the material for reinforcing is selected fro the group comprising bismuth alloy and zinc alloy. 